Wiseco WK1100 Pro-Lite Forged Piston Kit Kawasaki 900 ZXI STX STS 73mm

The Wiseco WK1100 is a Pro-Lite forged piston kit designed for Kawasaki 900 series personal watercraft engines. Built to a 73mm standard bore diameter (Wiseco part code 659M), this kit delivers the strength, precision, and durability that serious PWC riders and performance builders demand from a top-tier forged piston.

What's Included:

• Forged aluminum piston
• Piston ring(s)
• Wrist pin
• Circlips

Key Features:

• High-Silicon Forged Aluminum Construction — Wiseco pistons are forged from a high-silicon, low-expansion aluminum alloy, delivering superior tensile strength, reduced reciprocating weight, improved heat transfer, and extended service life compared to cast alternatives.
• Pro-Lite Design — The Pro-Lite profile is CNC-machined for an optimized cam shape and skirt profile, maximizing power output while minimizing friction and wear.
• Diamond-Turned Finish — Each piston is finish-machined on CNC turning centers to ensure a precise, consistent bore size with no variation—guaranteeing proper fit and seal every time.
• Universal Cylinder Compatibility — Compatible with cast iron, chrome, Nikasil, and boron composite cylinder bore compositions for broad fitment confidence.
• Oversize Availability — Available in a range of oversize bores to accommodate cylinder refresh and resleeving projects.
• Engineered and Forged in the USA — Manufactured at Wiseco's facility in Mentor, Ohio, using aerospace-grade alloys and state-of-the-art CNC equipment.

The WK1100 is the trusted choice for restoring or upgrading the two-stroke engine in Kawasaki 900 series personal watercraft. Wiseco's decades of motorsports heritage and rigorous quality standards make this piston kit a benchmark for performance and reliability in the PWC market.